In recent years, concern for the welfare of workers in hazardous jobs has increased considerably. In order to safeguard workers working in hazardous environments, clothing incorporating various impermeable and adsorptive materials has been used. Many of these materials have disadvantages in that they inhibit water vapor transmission and possess a finite capacity to adsorb chemicals. For example, carbon based technologies allowing water vapor transmission have limited adsorption capacity.
Moreover, the environmental impact of protective apparel remains a challenge for the industry. Concerns have arisen as to the deleterious effect of disposable clothing on the environment. There is a need to develop new protective garments that are reusable.
A preferred approach to protective garments providing comfort, flexibility and breathability relies on the use of selectively permeable materials. The use of selectively permeable materials is well known in the art and is described, for example, in U.S. Pat. Nos. 4,943,475, 5,391,426 and 6,395,383. These permeable materials are permeable only to water vapor as opposed to chemical, noxious or harmful agents. Generally, selectively permeable materials that possess high water vapor transmission are hydrophilic polymers like polyethylenimine (PEI), polyvinyl alcohol (PVOH) and polyvinyl alcohol co-ethylene. However, these water-soluble polymers offer poor chemical protection after laundering and as such cannot be considered reusable.
Therefore, there is a need to develop selectively permeable materials that offer a greater resistance to water and laundering and that have better binding properties to commercially available membranes while still acting as effective barriers against noxious or harmful agents, and while still maintaining their flexibility and breathability.
It is an object of this invention to provide a composition which has enhanced resistance to water and laundering, can better adhere to fabric or other solid supports and has enhanced water vapour permeability.